s390/topology: add detection of dedicated vs shared CPUs

The topology information returned by STSI 15.x.x contains a flag
if the CPUs of a topology-list are dedicated or shared. Make this
information available if the machine provides topology information.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 50 insertions, 3 deletions

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 1cee6753d47a..b9fc9b00d845 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -800,6 +800,8 @@ void __init smp_detect_cpus(void)
  */
 static void smp_start_secondary(void *cpuvoid)
 {
+	int cpu = smp_processor_id();
+
 	S390_lowcore.last_update_clock = get_tod_clock();
 	S390_lowcore.restart_stack = (unsigned long) restart_stack;
 	S390_lowcore.restart_fn = (unsigned long) do_restart;
@@ -813,8 +815,12 @@ static void smp_start_secondary(void *cpuvoid)
 	init_cpu_timer();
 	vtime_init();
 	pfault_init();
-	notify_cpu_starting(smp_processor_id());
-	set_cpu_online(smp_processor_id(), true);
+	notify_cpu_starting(cpu);
+	if (topology_cpu_dedicated(cpu))
+		set_cpu_flag(CIF_DEDICATED_CPU);
+	else
+		clear_cpu_flag(CIF_DEDICATED_CPU);
+	set_cpu_online(cpu, true);
 	inc_irq_stat(CPU_RST);
 	local_irq_enable();
 	cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c
index ed0bdd220e1a..d49940fb43b1 100644
--- a/arch/s390/kernel/topology.c
+++ b/arch/s390/kernel/topology.c
@@ -133,6 +133,7 @@ static void add_cpus_to_mask(struct topology_core *tl_core,
 			topo->socket_id = socket->id;
 			topo->core_id = rcore;
 			topo->thread_id = lcpu + i;
+			topo->dedicated = tl_core->d;
 			cpumask_set_cpu(lcpu + i, &drawer->mask);
 			cpumask_set_cpu(lcpu + i, &book->mask);
 			cpumask_set_cpu(lcpu + i, &socket->mask);
@@ -273,6 +274,14 @@ void store_topology(struct sysinfo_15_1_x *info)
 	stsi(info, 15, 1, topology_mnest_limit());
 }
 
+static void __arch_update_dedicated_flag(void *arg)
+{
+	if (topology_cpu_dedicated(smp_processor_id()))
+		set_cpu_flag(CIF_DEDICATED_CPU);
+	else
+		clear_cpu_flag(CIF_DEDICATED_CPU);
+}
+
 static int __arch_update_cpu_topology(void)
 {
 	struct sysinfo_15_1_x *info = tl_info;
@@ -298,6 +307,7 @@ int arch_update_cpu_topology(void)
 	int cpu, rc;
 
 	rc = __arch_update_cpu_topology();
+	on_each_cpu(__arch_update_dedicated_flag, NULL, 0);
 	for_each_online_cpu(cpu) {
 		dev = get_cpu_device(cpu);
 		kobject_uevent(&dev->kobj, KOBJ_CHANGE);
@@ -435,9 +445,39 @@ static struct attribute_group topology_cpu_attr_group = {
 	.attrs = topology_cpu_attrs,
 };
 
+static ssize_t cpu_dedicated_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	int cpu = dev->id;
+	ssize_t count;
+
+	mutex_lock(&smp_cpu_state_mutex);
+	count = sprintf(buf, "%d\n", topology_cpu_dedicated(cpu));
+	mutex_unlock(&smp_cpu_state_mutex);
+	return count;
+}
+static DEVICE_ATTR(dedicated, 0444, cpu_dedicated_show, NULL);
+
+static struct attribute *topology_extra_cpu_attrs[] = {
+	&dev_attr_dedicated.attr,
+	NULL,
+};
+
+static struct attribute_group topology_extra_cpu_attr_group = {
+	.attrs = topology_extra_cpu_attrs,
+};
+
 int topology_cpu_init(struct cpu *cpu)
 {
-	return sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
+	int rc;
+
+	rc = sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
+	if (rc || !MACHINE_HAS_TOPOLOGY)
+		return rc;
+	rc = sysfs_create_group(&cpu->dev.kobj, &topology_extra_cpu_attr_group);
+	if (rc)
+		sysfs_remove_group(&cpu->dev.kobj, &topology_cpu_attr_group);
+	return rc;
 }
 
 static const struct cpumask *cpu_thread_mask(int cpu)
@@ -509,6 +549,7 @@ void __init topology_init_early(void)
 	alloc_masks(info, &drawer_info, 3);
 out:
 	__arch_update_cpu_topology();
+	__arch_update_dedicated_flag(NULL);
 }
 
 static inline int topology_get_mode(int enabled)